Method for turbo transmission of digital broadcasting transport stream, a digital broadcasting transmission and reception system, and a signal processing method thereof

ABSTRACT

A digital broadcasting transmission/reception system, and a signal processing method thereof for turbo-processing digital broadcasting transport stream and transmitting the processed stream, includes a parity area generating unit preparing a first area for parity insertion with respect to a dual transport stream (TS) which includes a normal stream and a turbo stream as multiplexed, a first interleaver interleaving the dual TS which is transmitted from the parity area generating unit, a turbo processing unit detecting the turbo stream from the interleaved dual TS, exclusively encoding the detected turbo stream for turbo-processing, and stuffing the encoded turbo stream into the dual TS, a deinterleaver deinterleaving the dual TS which is processed by the turbo processing unit, and a transmitting unit transmitting the dual TS which is processed at the deinterleaver.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/416,253, filed on May 3, 2006, now pending, which claims the benefitof U.S. Provisional Application No. 60/724,786, filed on Oct. 11, 2005in the United States Patent and Trademark Office, and Korean PatentApplication No. 2005-113662, filed on Nov. 25, 2005 in the KoreanIntellectual Property Office, the disclosures of which are incorporatedherein by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Aspects of the invention relate to a method for turbo processing andtransmitting a digital broadcasting transport stream, a digitalbroadcasting reception and transmission system, and a method ofprocessing signals thereof. More particularly, aspects of the inventionrelate to a method for turbo processing and transmitting a digitalbroadcasting transport stream to enhance reception performance of aterrestrial-wave digital television (DTV) system in the U.S. inaccordance with the Advanced Television Systems Committee (ATSC)vestigial sideband (VSB) transmission system through informationexchange and mapping with respect to a dual transport stream (TS) whichincludes normal data and turbo data, and a digital broadcastingtransmission and reception system.

2. Description of the Related Art

The Advanced Television Systems Committee (ATSC) vestigial sideband(VSB) transmission system, which is used in a terrestrial-wave digitaltelevision (DTV) system in the U.S., is a single-carrier system thattransmits one field synchronization (sync) segment for each unit of 312data segments. Therefore, reception performance of the ATSC VSB systemis inferior over weak channels, especially over a Doppler-fadingchannel.

FIG. 1 is a block diagram of an ATSC VSB digital broadcastingtransceiver of the related art. The digital broadcasting transceivershown in FIG. 1 is configured in accordance with an enhanced VSB (E-VSB)system proposed by Phillips, and produces and transmits a dual streamconfigured by adding enhanced or robust data to normal data of thestandard ATSC VSB system.

As shown in FIG. 1, a digital broadcasting transmitter includes arandomizer 11, a Reed-Solomon (RS) encoder 12 having a concatenatedencoder form adding parity bytes to a dual transport stream to enableerrors generated by channel impairments during transmission to becorrected during reception, an interleaver 13 interleaving theRS-encoded data according to a predetermined pattern, and a 2/3 ratetrellis encoder 14 performing trellis-encoding at a rate of 2/3 withrespect to the interleaved data and mapping the interleaved data to8-level symbols. With this structure, the digital broadcastingtransmitter performs error-correction encoding with respect to the dualstream.

The digital broadcasting transmitter further includes a multiplexer 15inserting field synchronization (sync) and segment sync in theerror-correction encoded data according to a data format shown in FIG.2, and a modulator 16 inserting a pilot by adding a predetermined directcurrent (DC) value to the data symbols and the inserted segment sync andfield sync, amplitude-modulating the resulting signal onto anintermediate frequency (IF) carrier, filtering the resulting IF signalto produce a vestigial sideband (VSB) signal, up-converting the VSBsignal to a radio-frequency (RF) signal having a frequency of a desiredchannel, and transmitting the RF signal through the channel.

Accordingly, in the digital broadcasting transmitter, the normal dataand the enhanced or robust data are multiplexed according to the dualstream system that transmits the normal data and the enhanced or robustdata on one channel and are inputted to the randomizer 11. The inputteddata is randomized by the randomizer 11, and the randomized data isouter-encoded by the RS encoder 12 which is an outer encoder. Theinterleaver 13 distributes the encoded data according to thepredetermined pattern. The interleaved data is inner-encoded by thetrellis encoder 14 in 12-symbol units. The inner-encoded data is mappedto 8-level symbols. The field sync and the segment sync are inserted inthe mapped data. The pilot is inserted and the VSB modulation isperformed. The VSB signal is up-converted to the RF signal, and the RFsignal is transmitted through the channel.

A digital broadcasting receiver shown in FIG. 1 includes a tuner (notshown) converting the RF signal received through the channel to abaseband signal, a demodulator 21 performing synchronization detectionand demodulation with respect to the baseband signal, an equalizer 22compensating for channel distortion generated by multiple transmissionpaths with respect to the demodulated signal, a Viterbi decoder 23correcting errors of the equalized signal and decoding theerror-corrected signal to symbol data, a deinterleaver 24 rearrangingthe symbol data according to the predetermined pattern by which data wasdistributed by the interleaver 13 of the digital broadcastingtransmitter, an RS decoder 25 correcting errors, and a derandomizer 26derandomizing the data corrected by the RS decoder 25 and outputting anMPEG-2 (Moving Picture Experts Group) transport stream. Therefore, thedigital broadcasting receiver of FIG. 1 down-converts the RF signal tothe baseband signal in a reverse order relative to the digitalbroadcasting transmitter, demodulates and equalizes the convertedsignal, and performs channel-decoding, thereby recovering the originalsignal.

FIG. 2 shows a VSB data frame where the segment sync and the field syncare inserted according to an 8-VSB system which is used in the DTVsystem in the U.S. As shown in FIG. 2, one frame includes two fields.One field includes one field sync segment which is a first segment ofthe field, and 312 data segments. In the VSB data frame, one segmentcorresponding to one MPEG-2 packet comprises a 4-symbol segment sync and828 data symbols. The segment sync and the field sync in FIG. 2 are usedfor synchronization and equalization in the digital broadcastingreceiver. More specifically, the segment sync and the field sync, whichare known to the digital broadcasting transmitter and receiver, are usedas reference signals when the receiver performs synchronization andequalization. The U.S. terrestrial-wave digital broadcasting system ofFIG. 1 is configured to produce and transmit the dual stream by addingthe enhanced or robust data to the normal data of the ATSC VSB system ofthe related art. Therefore, the U.S. terrestrial-wave digitalbroadcasting system transmits the enhanced or robust data as well as thenormal data.

Although the enhanced or robust data is transmitted in the dual streamin addition to the normal data, inferior reception performance due tomultipath channel distortion caused by transmission of the normal datastream is not remarkably improved. In fact, almost no improvement in thereception performance is obtained by the improved normal data stream.Moreover, reception performance is not much improved with respect to theenhanced or robust stream, either.

SUMMARY OF THE INVENTION

Accordingly, an aspect of the invention is to provide a method for turboprocessing and transmitting a digital broadcasting transport stream toenhance reception performance of a terrestrial-wave digital television(DTV) in the US in accordance with the advanced television systemcommittee (ATSC) vestigial sideband (VSB) through information exchangeand mapping with respect to a dual transport stream (TS) which includesnormal data and turbo data, a digital broadcasting transmission andreception system, and a signal-processing method thereof.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be obviousfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofembodiments of the invention, taken in conjunction with the accompanyingdrawings, of which:

FIG. 1 is a block diagram showing a digital broadcasting transceiver ofthe related art according to the Advanced Television Systems Committee(ATSC) vestigial sideband (VSB) system;

FIG. 2 shows an exemplary frame structure of a VSB data frame used inthe digital broadcasting transceiver of the related art shown in FIG. 1;

FIG. 3 is a block diagram showing a digital broadcasting transmissionsystem according to an embodiment of the invention;

FIG. 4 is a block diagram provided to explain in detail the structure ofthe digital broadcasting transmission system of FIG. 3;

FIG. 5 is a block diagram showing a transport stream (TS) constructingunit of the digital broadcasting transmission system of FIG. 4;

FIG. 6 is a block diagram showing in detail the structure of atransmitting unit of the digital broadcasting transmission system ofFIG. 4;

FIG. 7 is a block diagram showing an example of a turbo processing unitof the digital broadcasting transmission system of FIG. 4;

FIG. 8 is a block diagram showing the structure of a turbo encoder ofthe turbo processing unit of FIG. 7;

FIGS. FIGS. 9A through 9H show exemplary structures of a dual transportstream packet of the digital broadcasting transmission system of FIG. 4;

FIG. 10 is a block diagram showing a digital broadcasting transmissionsystem that transmits a supplementary reference sequence (SRS) accordingto an embodiment of the invention;

FIGS. 11A through 11H show exemplary structures of a dual transportstream packet including the supplementary reference sequence (SRS) ofthe digital broadcasting transmission system of FIG. 10;

FIG. 12 is a block diagram showing the structure of a digitalbroadcasting reception system according to an embodiment of theinvention;

FIG. 13 is a block diagram of a turbo decode of the digital broadcastingreception system of FIG. 12;

FIG. 14 is a flowchart for explaining an example of a signal processingmethod in the digital broadcasting transmission system of FIG. 6;

FIG. 15 is a flowchart for explaining an example of a signal processingmethod in the turbo processing unit of FIG. 7;

FIG. 16 is a flowchart for explaining an example of a signal processingmethod in the digital broadcasting reception system of FIG. 12; and

FIG. 17 is a flowchart for explaining an example of a signal processingmethod in the turbo decoder of FIG. 13.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to embodiments of the invention,examples of which are shown in the accompanying drawings, wherein likereference numerals refer to like elements throughout. The embodimentsare described below in order to explain the invention by referring tothe figures. The specific structures and elements in the followingdescription are merely to assist in obtaining a comprehensiveunderstanding of the invention. Thus, it is apparent that the inventioncan be implemented without using these specific structures and elements.Also, well-known functions, structures, and elements have not beendescribed in detail in the following description to avoid obscuring theinvention with unnecessary details.

The following description presumes a familiarity with the AdvancedTelevision Systems Committee (ATSC) Digital Television (DTV) Systemwhich incorporates aspects of the MPEG-2 system, details of which aredescribed in the corresponding standards. Examples of such standardswhich may be relevant are ATSC A/52B, Digital Audio Compression Standard(AC-3, E-AC-3), Revision B, 14 Jun. 2005; ATSC A/53E, ATSC DigitalTelevision Standard (A/53), Revision E, 27 Dec. 2005; ATSC A/54A,Recommended Practice: Guide to the Use of the ATSC Digital TelevisionStandard, 4 Dec. 2003; ISO/IEC IS 13818-1:2000(E), Informationtechnology—Generic coding of moving pictures and associated audioinformation: Systems (second edition) (MPEG-2); and ISO/IEC IS13818-2:2000(E), Information technology—Generic coding of movingpictures and associated audio information: Video (second edition)(MPEG-2), the contents and disclosures of which are incorporated hereinby reference. However, it is understood that aspects of the inventioncan be implemented according to other standards and systems withoutrestriction. Moreover, the following description uses the terms “turbo”and “turbo data” which are represented in some of the drawings by theterms “robust” and “robust data”.

FIG. 3 is a block diagram showing a digital broadcasting transmissionsystem according to an embodiment of the invention. Referring to FIG. 3,the digital broadcasting transmission system includes a parity areagenerating unit 110, a first interleaver 120, a turbo processing unit130, a deinterleaver 140, and a transmitting unit 150. The parity areagenerating unit 110 provides an area for the insertion of parity bytesin a dual transport stream (TS), which includes a normal stream and aturbo stream. In other words, the parity is computed with respect to thedual TS, and inserted (that is, recorded in bits) into the parity area.The parity area provided by the parity area generating unit 110 will becalled “a first parity insertion area” in the following description.

The first interleaver 120 interleaves the dual TS which has an areaprovided by the parity area generating unit 110 for parity insertion.The turbo processing unit 130 detects the turbo stream included in theinterleaved dual TS, turbo-processes the detected turbo TS, and stuffsthe dual TS. While not required in all aspects, it is understood thatthe turbo processing of the turbo processing unit 130 may includeencoding processes such as convolution encoding with respect to theturbo TS to make the data turbo.

The deinterleaver 140 deinterleaves the dual TS outputted from the turboprocessing unit 130. The transmitting unit 200 transmits the dual TSafter it has been processed in the deinterleaver 140. The structure ofthe transmitting unit 200 will be described below in detail.

According to the embodiment shown in FIG. 3, a turbo stream, which hasbeen treated with a separate turbo processing, is transmitted togetherwith the normal stream. Therefore, reception performance under multipathconditions or in a mobile environment improves, and at the same time,compatibility with existing normal stream transmission/reception systemis provided. It is further understood that the turbo data can be variousforms of data, such as audio, video, computer software, game data,music, shopping information, internet data, text, voice data, and othertypes of data transmitted in addition to the normal data. Additionally,the normal data can include other data in addition to or instead of theaudio-video data used in digital broadcasting according to aspects ofthe invention.

The digital broadcasting transmission system of FIG. 3 will be explainedin greater detail below with reference to the block diagram of FIG. 4.Referring to FIG. 4, the digital broadcasting transmission systemfurther includes a transport stream (TS) generating unit 300 and arandomizer unit 150. The TS generating unit 300 generates a dual TS byreceiving a normal stream and a turbo stream, processing the turbostream, and multiplexing the normal stream and the processed turbostream. While not required in all aspects, the normal stream and theturbo stream may be received from an external module such as abroadcasting camera, or internal modules such as compression module suchas MPEG-2 module, a video encoder, and an audio encoder.

The randomizer unit 150 randomizes the dual TS generated by the TSgenerating unit 300 and provides it to the parity area generating unit110. Accordingly, the parity area generating unit 110 provides a parityarea for the dual TS. Since the elements in FIG. 4 other than the TSgenerating unit 300 and the randomizer unit 150 are same in function asthose of the above-described embodiment of FIG. 3, additionaldescription will be omitted for the sake of brevity.

An exemplary structure of the TS generating unit 300 will be describedbelow with reference to FIG. 5. The TS generating unit 300 includes afirst Reed-Solomon encoder 310, a pre-interleaver 320, a duplicator 330,and a service MUX (multiplexer) 340. Although the example shown in FIG.5 uses the first Reed-Solomon encoder 310 and the pre-interleaver 320,these can be omitted or replaced with other elements (not shown). It ispreferable, but not required, that the first Reed-Solomon encoder 310,when used, be used together with the pre-interleaver 320. The positionof the pre-interleaver 320 is interchangeable with that of theduplicator 330.

The first Reed-Solomon encoder 310 performs encoding by adding paritybytes to the received turbo stream. The pre-interleaver 320 interleavesthe turbo stream having the added parity bytes. The duplicator 330provides a parity area with respect to the interleaved turbo stream. Theparity area provided by the duplicator 330 will be called a “secondparity area” in the following description.

In order to provide the second parity area, the byte, which is the basicunit of the turbo stream, is divided into two or four bytes. A part ofbits of one byte, and null data such as 0, are then stuffed in each ofthe bytes. The area stuffed with the null data becomes the parity area.

The service MUX 340 multiplexes the normal stream which is separatelyreceived with the turbo stream processed in the duplicator 330. As thedual TS is generated, the service MUX 340 provides the dual TS to therandomizer unit 150.

An exemplary structure of the transmitting unit 200 of the digitalbroadcasting transmission system of FIG. 4 will be explained below withreference to the block diagram of FIG. 6. As shown in FIG. 6, thetransmitting unit 200 includes a second Reed-Solomon encoder 210, asecond interleaver 220, a trellis encoder 230, a MUX 240, and amodulator 250. The second Reed-Solomon encoder 210 encodes the dual TSreceived from the deinterleaver 140 by adding the parity bytes to thedual TS. More specifically, the second Reed-Solomon encoder 210 insertsparity bytes computed with respect to the dual TS in the first parityarea provided by the parity area generating unit 110.

The second interleaver 220 interleaves the dual TS having the addedparity bytes added by the second Reed-Solomon encoder 210. The trellisencoder 230 encodes the dual TS after the dual TS is interleaved by thesecond interleaver 220. The MUX 240 multiplexes the dual TS after thetrellis encoding by adding segment sync and field sync to the dual TS.The modulator 250 modulates channel of the dual TS after themultiplexing, and up-converts into a signal of RF channel band.Accordingly, the dual TS is transmitted to a variety of receptionsystems via the channel. Although not shown in FIG. 6 and while notrequired in all aspects, the transmission unit 200 may additionallyinclude general components for the signal transmission, such as a poweramplifier (not shown) which amplifies the power of the modulated signalof the modulator 250, and an antenna (not shown), and may furtherinclude elements used to broadcast within cable, internet, and/orsatellite systems and media through which digital broadcasts can beimplemented.

An exemplary structure of the turbo processing unit 130 of the digitalbroadcasting transmission system of FIG. 4 will be explained below withreference to the block diagram of FIG. 7. With reference to FIG. 7, theturbo processing unit 130 includes a byte/symbol converting unit 131, ade-MUX 132, a turbo encoder 133, a turbo interleaver 134, a turbo dataMUX 135, and a symbol/byte converting unit 136. The byte/symbolconverting unit 131, the de-MUX 132, the turbo data MUX 135, and thesymbol/byte converting unit 136 may be omitted, or replaced with othercomponents in other aspects of the invention.

The byte/symbol converting unit 131 converts the basic unit of theinterleaved dual TS of the first interleaver 120 from bytes to symbols.Conversion of the basic unit from byte to symbol will be easilyunderstood with reference to the table D5.2 of U.S. ATSC DTV standard(A/53), the contents of which are incorporated herein by reference intheir entirety.

The de-MUX 132 demultiplexes the dual TS of symbol unit to recover theturbo stream. The turbo encoder 133 computes parity bytes with respectto the detected turbo stream, and encodes the turbo stream by stuffingthe second parity area with the computed parity bytes. In thisparticular example, the turbo encoder 133 performs encoding in the unitof each byte of the turbo stream. However, it is understood that otherunits can be used.

The turbo interleaver 134 interleaves the turbo stream which isconvolution-encoded. In this example, the turbo interleaver 134interleaves in the unit of bit. The turbo data MUX 135 generates a dualTS by multiplexing the interleaved turbo stream and the normal stream.More specifically, the turbo data MUX 135 constructs a dual TS bystuffing the turbo stream to the place before it is detected by thede-MUX 132. The symbol/byte converting unit 136 converts the basic unitof the dual TS from symbols to bytes. This conversion will be easilyunderstood with reference to the table D5.2 of the U.S. ATSC DTVstandard (A/53), the disclosure of which is incorporated by reference.

An example of the byte-to-symbol table of table D5.2 is as follows:

Segment 0 Segment 1 Segment 2 Segment 3 Segment 4 Symbol Trellis ByteBits Trellis Byte Bits Trellis Byte Bits Trellis Byte Bits Trellis ByteBits 0 0 0 7.6 4 208 5.4 8 412 3.2 0 616 1.0 4 828 7.6 1 1 1 7.6 5 2095.4 9 413 3.2 1 617 1.0 5 829 7.6 2 2 2 7.6 6 210 5.4 10 414 3.2 2 6181.0 6 830 7.6 3 3 3 7.6 7 211 5.4 11 415 3.2 3 619 1.0 . . . . . . . . .4 4 4 7.6 8 212 5.4 0 416 3.2 4 620 1.0 . . . . . . . . . 5 5 5 7.6 9213 5.4 1 417 3.2 5 621 1.0 . . . . . . . . . 6 6 6 7.6 10 214 5.4 2 4183.2 6 622 1.0 . . . . . . . . . 7 7 7 7.6 11 215 5.4 3 419 3.2 7 623 1.0. . . . . . . . . 8 8 8 7.6 0 204 5.4 4 408 3.2 8 612 1.0 . . . . . . .. . 9 9 9 7.6 1 205 5.4 5 409 3.2 9 613 1.0 . . . . . . . . . 10 10 107.6 2 206 5.4 6 410 3.2 10 614 1.0 . . . . . . . . . 11 11 11 7.6 3 2075.4 7 411 3.2 11 615 1.0 . . . . . . . . . 12 0 0 5.4 4 208 3.2 8 4121.0 0 624 7.6 . . . . . . . . . 13 1 1 5.4 5 209 3.2 9 413 1.0 1 625 7.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . 19 7 7 5.4 11 215 3.2 3 4191.0 7 631 7.6 . . . . . . . . . 20 8 8 5.4 0 204 3.2 4 408 1.0 8 632 7.6. . . . . . . . . 21 9 9 5.4 1 205 3.2 5 409 1.0 9 633 7.6 . . . . . . .. . 22 10 10 5.4 2 206 3.2 6 410 1.0 10 634 7.6 . . . . . . . . . 23 1111 5.4 3 207 3.2 7 411 1.0 11 635 7.6 . . . . . . . . . 24 0 0 3.2 4 2081.0 8 420 7.6 0 624 5.4 . . . . . . . . . 25 1 1 3.2 5 209 1.0 9 421 7.61 625 5.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . 31 7 7 3.2 11 2151.0 3 427 7.6 . . . . . . . . . . . . . . . . . . 32 8 8 3.2 0 204 1.0 4428 7.6 . . . . . . . . . . . . . . . . . . 33 9 9 3.2 1 205 1.0 5 4297.6 . . . . . . . . . . . . . . . . . . 34 10 10 3.2 2 206 1.0 6 430 7.6. . . . . . . . . . . . . . . . . . 35 11 11 3.2 3 207 1.0 7 431 7.6 . .. . . . . . . . . . . . . . . . 36 0 0 1.0 4 216 7.6 8 420 5.4 . . . . .. . . . . . . . . . . . . 37 1 1 1.0 5 217 7.6 9 421 5.4 . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . 47 11 11 1.0 3 227 7.6 . . .. . . . . . . . . . . . . . . . . . . . . . . . 48 0 12 7.6 4 216 5.4 .. . . . . . . . . . . . . . . . . . . . . . . . . . 49 1 13 7.6 5 2175.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 95 11 23 1.0 . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 96 0 24 7.6 . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . 97 1 25 7.6 . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .767 11 191 1.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . 768 0 192 7.6 . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . 769 1 193 7.6 . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 815 11203 1.0 3 419 7.6 7 623 5.4 11 827 3.2 . . . . . . . . . 816 0 204 7.6 4408 5.4 8 612 3.2 0 816 1.0 . . . . . . . . . 817 1 205 7.6 5 409 5.4 9613 3.2 1 817 1.0 . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 827 11 2157.6 3 419 5.4 7 623 3.2 11 827 1.0 . . . . . . . . .

An exemplary structure of the turbo encoder 133 of the turbo processingunit 130 of FIG. 7 will now be explained with reference to the blockdiagram of FIG. 8. According to FIG. 8, the turbo encoder 133 includes ashift register having three elements D and two adders. Accordingly, theturbo encoder 133 convolution-encodes the data to recursive systematicconvolutional (RSC) code, to insert parities in the second parity area.

FIGS. 9A through 9H show exemplary structures of the dual TS of thedigital broadcasting transmission system of FIG. 4. FIG. 9A shows anexample of a turbo stream packet received by the TS structure unit 300.The turbo stream packet may comprise 188 bytes, for example. In thiscase, more particularly, the turbo stream packet comprises 1 byte ofsync which is a header, 3 bytes of packet identity (PID), and 184 bytesof turbo data.

FIG. 9B shows an example of a normal stream packet received by the TSstructure unit 300. The normal stream packet may comprise 188 bytes,more particularly, 1 byte of sync that is a header, 2 bytes of anadaptation field (AF) header, N bytes of null data, and 182-N bytes ofnormal data. The AF header is an area where information about anadaptation field is recorded, so it contains information such as alocation, a size, and so on of the adaptation field.

FIG. 9C shows an example of a dual TS (or, a stream packet) generated bythe TS generating unit 300. In FIG. 9C, a part of the turbo streampacket of FIG. 9A is inserted in the null data of the normal streampacket of FIG. 9B. In this embodiment, the dual TS comprises 188 bytes,more particularly, 1 byte of sync which is a header, 3 bytes of PID, 2bytes of an AF header, N bytes of null data, and 182-N bytes of normaldata which is a payload. The inserted turbo data shown in FIG. 9C may bea part of the turbo stream packet of FIG. 9A. For example, the insertedturbo data of FIG. 9C may be at least one of the sync, the PID, and theturbo data of FIG. 9A.

FIG. 9D shows a dual TS generated by the TS generating unit 300according to another embodiment of the invention. According to theembodiment shown in FIG. 9D, the dual TS includes a plurality ofconsecutive packets. Turbo data is arranged with respect to apredetermined number of packets. That is, FIG. 9D shows that 78-packetturbo streams are inserted in 312-segment packets of one field of thedual TS. The dual TS comprises 1 packet (188 bytes) of the turbo streamand 3 consecutive packets (188 bytes) of the normal streams which arerepeatedly arranged at the rate of 1:3.

In case that 70-packet turbo streams are inserted in 312-segment packetsof the dual TS, the dual TS is structured in a manner that 4 packetscomprising 1 packet (188 bytes) of the turbo streams and 3 consecutivepackets (188 bytes) of the normal streams are repeatedly arranged 70times, and the rest 32 packets comprise the normal stream packets.

FIG. 9E shows a dual TS packet structured by the TS structure unit 300,according to yet another embodiment of the invention. 88 packets of theturbo streams are inserted in 312 segments of the packets of one fieldof the dual TS. The dual TS is structured in a manner that 4 packetscomprising 2 packets (188 bytes) of the turbo streams and 2 packets (188bytes) of the normal streams are repeatedly arranged 10 times, and 4packets comprising 1 packet (188 bytes) of the turbo stream and 3consecutive packets (188 bytes) of the normal streams are repeatedlyarranged at the rate of 1:3 as shown in FIG. 9D.

FIG. 9F shows a dual TS structured by the TS structure unit 300,according to still another embodiment of the invention, which is acombined form of the dual TS shown in FIGS. 9C and 9D. The dual TS isstructured in a manner that 4 packets are repeatedly arranged, the 4packets comprising 1 packet (188 bytes) of the turbo stream, 1 packet ofthe normal stream wherein SRS data and the turbo data are inserted in apart of the AF of the normal stream packet, and 2 packets (188 bytes) ofthe normal stream packets.

FIGS. 9G and 9H show the dual TS which is structured in the form of312-segment packets. As shown in FIGS. 9G and 9H, packet information,along with the turbo data and the normal data, is included in the dualTS. The packet information may be recorded in the option field. In thiscase, locations of option field can be designated and fixed so as not tooverlap with the turbo data. In FIGS. 9G and 9H, “m” denotes a possiblelength (byte) of the turbo data.

According to FIGS. 9G and 9H, the option fields recording the number ofmacro blocks (splice countdown) are arranged in the segments 11, 63,115, 167, 219, 271, while the option fields recoding program clockreference (PCR) are arranged in the segments 15, 67, 119.

When dividing the 312 segments into 52-segment units, the locations ofthe option fields can be expressed as follows:

Program clock reference (PCR) (using 6 bytes): 52n+15, n=0;

Original program clock reference (OPCR) (using 6 bytes): 52n+15, n=1;

Adaptation field extension length (using 2 bytes): 52n+15, n=2;

Transport private data length (using 5 bytes): 52n+15, n=3, 4, 5; and

a number of macro blocks (splice countdown) (using 1 byte): 52n+15, n=0,1, 2, 3, 4, 5

The “transport private data length” among these, for example, exists inthe segments 171, 223, 275. The dual TS in which the turbo data isinserted in the null data except the option fields can be structured invarious ways besides the above-introduced ways. Additionally, thestructural rate of the turbo data can be adjusted according to thestructure of the dual TS packet.

FIG. 10 is a block diagram showing a digital broadcasting transmissionsystem that transmits a supplementary reference sequence (SRS). Whiledescribed in the context of SRS, it is understood that other trainingsequences and/or sets of known data can be implemented in other aspectsof the invention. Referring to FIG. 10, the digital broadcastingtransmission system includes a TS structure unit 801 including astuffing region to insert SRS data in respective packets of the dual TS,a randomizer 803 randomizing the dual TS packet (hereinafter, referredto as merely “packet”), a supplementary reference sequence insertingunit 805 inserting the SRS data in the stuffing region of the randomizedpacket, a parity area generating unit 807 generating a first area forinserting a parity for error correction, a first interleaver 809primarily interleaving the packet where the first area is generated, aturbo processing unit 811 convolution-encoding and interleaving theturbo stream included in the primarily interleaved packet, adeinterleaver 813 deinterleaving the packet processed by the turboprocessing unit 811, a Reed-Solomon (RS) encoder 815 inserting theparity in the first area of the deinterleaved packet, a secondinterleaver 817 secondarily interleaving the packet where the parity isinserted, a trellis encoder 819 trellis encoding the interleaved packet,a MUX 823 multiplexing the trellis-encoded packet by adding a sync, anda modulator 825 channel-modulating and transmitting the multiplexedpacket. Additionally, a backwards compatibility parity generator 821generating a compatible parity may be further included.

Known SRS data for synchronization and/or channel equalization may beinserted in the dual TS packet received by the digital broadcastingtransmission, which will be described in detail with reference to FIG.9. The TS structure unit 801 receives the normal stream and the turbostream and structures the dual TS packet. According to an embodiment ofthe invention, the dual TS packet may include a stuffing region forinserting therein the known SRS data for synchronization and/or channelequalization. The TS structure unit 801 may be constructed in the sameway as explained above with reference to FIG. 5, and therefore,description thereof will be omitted for the sake of brevity. If the TSstructure unit 801 includes the first Reed-Solomon encoder 310 as in theabove embodiment shown in FIG. 5, the Reed-Solomon encoder 815 of FIG.10 will be called as a second Reed-Solomon encoder for the conveniencein explanation.

The stuffing region for inserting therein the known SRS data forsynchronization and/or channel equalization will now be described. Thestuffing region may be a part of the packet including a header and apayload. More particularly, the packet further includes an adaptationfield (AF). The stuffing region as part of the AF is positioned not tobe overlapped with the option field included in the AF. The option fieldcomprises a program clock reference (PCR) used for synchronization of ademodulator of a receiver, an original PCR (OPCR) used for recording,reservation, and reproduction of a program in the receiver, four circuitblocks, the number of macro blocks (splice countdown) denoting thenumber of consecutive macro blocks comprising one Cr block and one Cbblock, transport private data length denoting length of text data forteletext broadcasting, and AF extension length.

According to an embodiment of the invention, the AF of the packet mayfurther include a stuffing region for inserting therein data forinitializing the trellis encoder 809 that will be described hereinafter.The randomizer 803 randomizes the packet including the stuffing region.

The SRS inserting unit 805 inserts the SRS data in the stuffing regionof the randomized packet. Here, the SRS data is a reference signal, thatis, specific sequence data having a pattern predetermined by thetransmitter and the receiver. Since the SRS data is different fromgeneral payload data transceiving the pattern of the reference signal,the SRS data can be detected easily from general packets to betransmitted and thereby used for synchronization of the receiver and/orchannel equalization. The insertion of the SRS data in the stuffingregion can be controlled by a predetermined controlling signal.

The parity area generating unit 807 generates a first area for insertingthe parity for error correction in the packet where the SRS data isinserted. As shown, the first area is for inserting therein the parityadded by the RS encoder 815. The first interleaver 809 primarilyinterleaves the packet where the parity area is generated. The turboprocessing unit 811 convolution-encodes the turbo stream included in theprimarily interleaved packet and interleaves the convolution-encodedturbo stream. The turbo processing unit 811 is configured as shown inFIG. 7 and operates in the same manner as described with reference toFIG. 7.

The deinterleaver 813 deinterleaves the packet output from the turboprocessing unit 811. The RS encoder 815 adds the parity to thedeinterleaved dual TS. According to an embodiment of the invention, theRS encoder 815, being structured in the form of concatenated code,inserts the parity to correct errors generated by the channel at thefirst area of the packet where the SRS data is inserted. The secondinterleaver 817 secondarily interleaves the packet where the parity isinserted. The trellis encoder 819 trellis encodes the secondarilyinterleaved packet.

According to an embodiment of the invention, the trellis encoder 819 canbe initialized to a predetermined value right before the SRS dataincluded in the interleaved packet is trellis-encoded. Theinitialization is required due to the SRS data. More specifically, thetrellis encoder 819 may generate different encoded results for the samedata depending on the previously encoded data. Therefore, the result oftrellis encoding of the SRS data may vary according to data previous tothe SRS data and in this case, the receiver cannot discriminate the SRSdata. To solve such a problem, the trellis encoder 819 is initialized tothe predetermined value right before trellis encoding of the SRS data.In other words, the predetermined value is trellis encoded right beforethe SRS data is trellis-encoded.

The trellis encoder 819 according to an embodiment of the invention mayinclude i) a general mode that trellis encodes the packet interleaved bythe interleaver, ii) an initialization mode that initializes the trellisencoder 819, and iii) a parity replacement mode that trellis-encodes thecompatible parity substituted for the whole or a part of the parityapplied by the RS encoder 815. For this purpose, the trellis encoder 819may receive a control signal from a control signal generation unit (notshown), the control signal operated in the general mode, theinitialization mode, or the parity replacement mode.

When the trellis encoder 819 receives a control signal commanding theinitialization mode while operating in the general mode, the trellisencoder 819 is operated in the initialization mode. If it receives acontrol signal commanding the parity replacement mode while it isoperating in the general mode, the trellis encoder 819 is operated inthe parity replacement mode. The control signal may be supplied from thecontrol signal generation unit (not shown) which is aware of location ofthe inserted SRS data, location of the inserted value for initializingthe trellis encoder 819, and location for replacing the compatibleparity.

The backwards compatibility parity generating unit 821 receives thepacket where the parity is added by the RS encoder 815 and the packetencoded by the trellis encoder 819, and generates the compatible paritybased on the received packets. More specifically, the backwardscompatibility parity generating unit 821 includes a symbol decoder (notshown) receiving the packet encoded by the trellis encoder 819 andconverting a symbol-mapped packet to a byte form, a deinterleaver (notshown) deinterleaving the decoded packet, and a memory (not shown)replacing at least a part of the received packet with the deinterleavedpacket and storing the deinterleaved packet. Preferably, the memory (notshown) may replace and store only the different part between thereceived packet and the deinterleaved packet. For this, the backwardscompatibility parity generating unit 821 may receive a predeterminedcontrol signal from the control signal generation unit (not shown), forexample. The memory (not shown) may include an RS encoder (not shown)adding the compatible parity to the packet stored in the memory, aninterleaver (not shown) interleaving the packet where the compatibleparity is added, and a symbol encoder (not shown) symbol-mapping thepacket in the byte form in order to transmit the interleaved packet tothe trellis encoder 819.

The MUX 823 multiplexes the trellis-encoded packet by adding the segmentsync and the field sync to the trellis-encoded packet. The modulator 825performs channel-modulation with respect to the packet where the segmentsync and the field sync are added, up-converts the modulated packet to asignal of an RF channel band, and transmits the converted signals.

FIGS. 11A through 11H show the structure of a TS packet including theSRS, according to an embodiment of the invention. FIG. 11A shows a turbostream packet received by the TS structure unit 801. The turbo streampacket (188 bytes) comprises 1 byte of sync which is a header, 3 bytesof PID, and 184 bytes of turbo data. FIG. 11B shows a normal streampacket including a stuffing region for inserting the known SRS signalfor synchronization in the TS structure unit. The normal stream packet(188 bytes) comprises 1 byte of sync which is a header, 3 bytes of PID,2 bytes of AF header, S-bytes of stuffing region, N-bytes of null data,and 182-N-S bytes of normal data which is a payload. FIG. 11C shows adual TS packet including the stuffing region for inserting the known SRSsignal for synchronization in the TS structure unit, according to anembodiment of the invention. More specifically, in FIG. 11C, part of theturbo stream packet of FIG. 11A is inserted in the null data of thenormal stream packet of FIG. 11B, and the SRS data is inserted in thestuffing region. In this embodiment, the dual TS comprises 188 bytes,more particularly, 1 byte of sync which is a header, 3 bytes of PID, 2bytes of AF header, S-bytes of SRS data, N-bytes of null data, and a182-N-S bytes of normal data which is a payload.

FIG. 11D shows a dual TS packet including the stuffing region forinserting the known SRS signal for synchronization in the TS structureunit, according to another embodiment of the invention. Differently fromthe dual TS packet of FIG. 9C, 78-packet turbo streams are inserted in312-segment packets of one field of the dual TS. The dual TS isstructured in a manner that 4 packets comprising 1 packet (188 bytes) ofthe turbo stream and 3 consecutive packets (188 bytes) of the normalstreams are repeatedly arranged at the rate of 1:3. When 70 packets ofthe turbo streams are inserted in 312 segments of the packets of thedual TS, on the other hand, the dual TS is structured in a manner that 4packets comprising 1 packet (188 bytes) of the turbo streams and 3consecutive packets (188 bytes) of the normal streams are repeatedlyarranged 70 times, and the rest 32 packets comprise the normal streampackets.

FIG. 11E shows a dual TS packet including the stuffing region forinserting the known SRS signal for synchronization in the TS structureunit, according to yet another embodiment of the invention. Differentlyfrom the dual TS packet of FIG. 9C, 88-packet turbo streams are insertedin 312-segment packets of one field of the dual TS. The dual TS isstructured in a manner that 4 packets comprising 2 packets (188 bytes)of the turbo streams and 2 packets (188 bytes) of the normal streams arerepeatedly arranged 10 times, and 4 packets comprising 1 packet (188bytes) of the turbo stream and 3 consecutive packets (188 bytes) of thenormal streams are repeatedly arranged at the rate of 1:3 as shown inFIG. 9D.

FIG. 11F shows a dual TS packet including the stuffing region forinserting the known SRS signal for synchronization in the TS structureunit, according to still another embodiment of the invention, which is acombined form of the dual TS packets shown in FIGS. 11C and 11D. Thedual TS packet is structured in a manner that 4 packets are repeatedlyarranged, the 4 packets comprising 1 packet (188 bytes) of the turbostream, 1 packet of the normal stream wherein the SRS data and the turbodata are inserted in a part of the AF of the normal stream packet, and 2packets (188 bytes) of the normal stream packets.

FIGS. 11G and 11H shows the dual TS packet including the stuffing regionfor inserting the known SRS signal for synchronization in the TSstructure unit, in the form of segment packets as shown in FIG. 11C.Among 312-segment packets of one field of dual TS, the turbo data isinserted in a non-option field part of the packet including data of theoption field. In FIGS. 11G and 11H, ‘k’ denotes a possible length (byte)of the SRS data. In addition, the turbo data is inserted next to the SRSdata. Here, ‘m’ denotes a possible length (byte) of the turbo data.

When dividing the 312 segments by 52-segment unit, location of theoption field can be expressed as follows:

Program clock reference (PCR) (using 6 bytes): 52n+15, n=0;

Original program clock reference (OPCR) (using 6 bytes): 52n+15, n=1;

Adaptation field extension length (using 2 bytes): 52n+15, n=2;

Transport private data length (using 5 bytes): 52n+15, n=3, 4, 5; and

The number of macro blocks (splice countdown) (using 1 byte): 52n+15,n=0, 1, 2, 3, 4, 5.

The “transport private data length” among these, for example, exists onthe location where n=3, 4, or 5.

The dual TS in which the turbo data is inserted in the null data exceptthe option field can be structured in various ways besides theabove-introduced ways. Additionally, the structural rate of the turbodata can be adjusted according to the structure of the dual TS packet.

FIG. 12 is a block diagram showing a digital broadcasting receptionsystem according to an embodiment of the invention. Referring to FIG.12, the digital broadcasting reception system comprises a modulator1001, an equalizer 1003, a first processor 1050, and a second processor1060. The digital broadcasting reception system receives the dual TS,demodulates the received dual TS, equalizes the demodulated dual TS,Viterbi-decodes and deinterleaves the normal stream of the equalizeddual TS, RS-decodes the deinterleaved normal stream, and derandomizesthe RS-decoded normal stream. The digital broadcasting reception systemturbo-decodes and deinterleaves the turbo stream of the equalized dualTS, RS-decodes the deinterleaved turbo stream, and derandomizes theRS-decoded turbo stream. The modulator 1001 performs synchronizationdetection and demodulation with respect to the baseband signal of thereceived dual TS. The equalizer 1003 compensates for channel distortiongenerated by multipaths of the channel from the demodulated dual TS,thereby removing interference between the received symbols.

The first processor 1050 includes a Viterbi decoder 1017, adeinterleaver 1021, an RS decoder 1023, and a derandomizer 1025. TheViterbi decoder 1017 performs error correction with respect to thenormal stream of the equalized dual TS and decodes the error-correctedsymbols, thereby outputting the symbol packet. The distributed decodedpacket can be rearranged by the deinterleaver 1021. The RS decoder 1023performs error correction with respect to the deinterleaved packet. Thederandomizer 1025 derandomizes the packet error-corrected by the RSdecoder 1023. Accordingly, the normal stream of the dual TS is restored.

The second processor 1060 includes a turbo decoder 1005, a seconddeinterleaver 1009, an RS decoder 1011, a derandomizer 1013, and a turboDE-MUX 1015. However, it is understood that the second processor 1060need not include all shown elements, such as the turbo DE-MUX 1015, inall aspects of the invention. The turbo decoder 1005 turbo-decodes theturbo stream of the equalized dual TS. The turbo decoding is performedby trellis-decoding the turbo stream of the equalized dual TS,deinterleaving and convolution-decoding the trellis-decoded turbostream, frame-formatting the convolution-decoded turbo stream, andthereby converting the turbo stream in the symbol form to the byte form.

Meanwhile, the turbo decoder 1005 is capable of trellis-decoding thenormal stream of the equalized dual TS. The trellis-decoded normalstream is converted from the symbol form to the byte form using asymbol-byte converter (not shown). The converted normal stream isdeinterleaved to remove the parity. The parity-removed normal stream isderandomized, thereby being restored.

The deinterleaver 1009 deinterleaves the turbo-decoded turbo stream. TheRS decoder 1011 removes the parity added to the deinterleaved turbostream. The derandomizer 1013 derandomizes the parity-removed turbostream. The turbo DE-MUX 1015 demultiplexes the derandomized turbostream. The turbo stream herein is capable of receiving the turbo dataamong the turbo stream demultiplexed and formatted to the frame form.

FIG. 13 is a block diagram of the turbo decoder of the digitalbroadcasting reception system of FIG. 12. Referring to FIGS. 12 and 13,the turbo decoder 1005 comprises a trellis decoder 2001, a turbodeinterleaver 2003, a turbo decoder 2005, a turbo interleaver 2007, aframe formatter 2009, and a symbol/bye converting unit 2011.

The trellis decoder 2007 trellis-decodes the equalized dual TS.According to this embodiment, the trellis decoder 2007 maytrellis-decode the turbo stream of the dual TS and also a soft decisionturbo stream which is turbo-interleaved. The turbo deinterleaver 2003deinterleaves the trellis-decoded turbo stream. The turbo decoder 2005convolution-decodes the deinterleaved turbo stream, thereby outputting asoft decision or a hard decision. “Soft decision” refers to a valueincluding information on a metric of the turbo stream. For example, whenthe metric of the turbo stream is “1” and when the metric of the turbostream results in “0.8”, the soft decision value “0.8” is output. Whenthe metric of the turbo stream results in “1”, the hard decision, thatis, the turbo stream, is output.

The turbo interleaver 2007 interleaves the hard decision turbo streamthat is convolution-decoded. The frame formatter 2009 formats theconvolution-decoded hard decision turbo stream corresponding to theframe of the dual TS.

The operation of the symbol/byte converter 2011 to convert theframe-formatted turbo stream from the symbol form to the byte form canbe easily understood by referring to Table D5.2 of the ‘ATSC DTVstandard (A/53)’ as set forth above.

FIG. 14 is a flowchart for explaining an example of a signal processingmethod in the digital broadcasting transmission system of FIG. 6.Referring to FIG. 14 and FIG. 6, the TS structure unit 300 receives thenormal stream and the turbo stream, generates the second area forinserting the parity in the received turbo stream, and multiplexes thereceived normal stream and the turbo stream where the second area isgenerated, thereby structuring the dual TS (S1201). The randomizer 150randomizes the dual TS output from the TS structure unit 300 (S1203).The parity area generator 110 generates the first area for inserting theparity for error correction in the randomized dual TS (S1205). The firstinterleaver 120 primarily interleaves the dual TS where the parity areais generated (S1207), and the turbo processing unit 130convolution-encodes the turbo stream included in the primarilyinterleaved dual TS and interleaves the convolution-encoded turbo stream(S1209). The deinterleaver 140 deinterleaves the dual TS output from theturbo processing unit 130 (S1211). The RS encoder 210 inserts the parityin the first area of the deinterleaved dual TS (S1213).

The second interleaver 220 secondarily interleaves the dual TS where theparity is inserted (S1215). The trellis-encoder 230 trellis-encodes thesecondarily interleaved dual TS (S1217). The MUX 240 multiplexes thetrellis-encoded dual TS by adding the segment sync and the field sync(S1219). The modulator 250 channel-modulates the multiplexed dual TS,up-converts the dual TS to a signal of a radio frequency (RF) channelband, and transmits the up-converted signal (S1221).

FIG. 15 is a flowchart for explaining an example of a signal processingmethod in the turbo processing unit of FIG. 7. Referring to FIG. 15 andFIG. 7, the byte-symbol converter 131 converts the primarily interleaveddual TS from the byte form to the symbol form (S1301). The TS DE-MUX 132demultiplexes the dual TS converted to the symbol form into the normalstream and the turbo stream (S1303). The turbo encoder 133convolution-encodes the turbo stream of the demultiplexed dual TS(S1305).

Through the convolution-encoding, the parity with respect to the turbostream is additionally generated and inserted in the second area of theturbo stream. The turbo interleaver 134 interleaves theconvolution-encoded turbo stream (S1307). The turbo data MUX 135multiplexes the interleaved turbo stream and the demultiplexed normalstream, thereby structuring the dual TS (S1309). The symbol-byteconverter 136 converts the dual TS from the symbol form to the byte form(S1311).

FIG. 16 is a flowchart for explaining an example of a signal processingmethod in the digital broadcasting reception system of FIG. 12.Referring to FIG. 16 and FIG. 12, the demodulator 1001 detects anddemodulates synchronization according to the sync added to the signal ofthe baseband of the received dual TS (S1401). The equalizer 1003compensates channel distortion generated by multipaths of the channelfrom the demodulated dual TS, thereby removing interference between thereceived symbols (S1403).

The Viterbi decoder 1005 of the first processor 1050 performs errorcorrection with respect to the normal stream of the equalized dual TS,decodes the error-corrected symbol, and outputs the symbol packet(S1405). The distributed decoded packet is rearranged by thedeinterleaver 1009 (S1407). The RS decoder 1023 performs errorcorrection with respect to the deinterleaved packet (S1409). Thederandomizer 1025 derandomizes the packet error-corrected by the RSdecoder 1023 (S1411). Accordingly, the normal stream of the dual TS isrestored.

The turbo decoder 1005 of the second processor 1060 turbo-decodes theturbo stream of the equalized dual TS (S1413). The turbo decoding isperformed by trellis-decoding the turbo stream of the equalized dual TS,deinterleaving and convolution-decoding the trellis-decoded turbostream, frame-formatting the convolution-decoded turbo stream, andthereby converting the turbo stream from the symbol form to the byteform. The deinterleaver 1009 deinterleaves the turbo-decoded turbostream (S1415). The RS decoder 1011 removes the parity added to thedeinterleaved turbo stream (S1417). The derandomizer 1013 derandomizesthe parity-removed turbo stream (S1419). The turbo DE-MUX 1015demultiplexes the derandomized turbo stream (S1421). The turbo streamherein is capable of receiving the turbo data among the turbo streamdemultiplexed and formatted to the frame form.

FIG. 17 is a flowchart for explaining an example of a signal processingmethod in the turbo decoder of FIG. 13. Referring to FIG. 17 and FIG.13, the trellis-decoder 2007 of the turbo decoder 1005 trellis-decodesthe equalized dual TS (S1501), the turbo deinterleaver 2003deinterleaves the trellis-decoded turbo stream (S1503), and the turbodecoder 2005 convolution-decodes the deinterleaved turbo stream (S1507),thereby outputting soft decision or hard decision. Here, the softdecision refers to a value including information on a metric of theturbo stream. For example, when the metric of the turbo stream is “1”and when the metric of the turbo stream results in “0.8”, the softdecision value “0.8” is output. When the metric of the turbo streamresults in “1”, the hard decision, that is, the turbo stream is output.The output soft decision is interleaved through the turbo interleaver2007 (S1505) and trellis-decoded for error correction. Therefore, theabove processes are repeated until the metric of the turbo streambecomes “1” to output the hard decision. Details of turbo coding per seare not provided because they are well known in the art. Moreover, theinvention is not limited to turbo coding, and aspects of the inventionmay use other types of coding in place of or in addition to turbocoding.

The frame formatter 2009 formats the convolution-decoded hard decisionturbo stream corresponding to the frame of the dual TS (S1509). Thesymbol-byte converter 2011 may convert the frame-formatted turbo streamfrom the symbol form to the byte form (S1511).

As can be appreciated from the above description of the method forturbo-processing and transmitting the TS for digital broadcasting, thedigital broadcasting transmission/reception system, and the signalprocessing method thereof, according to certain embodiments of theinvention, reception performance of a terrestrial-wave digitaltelevision (DTV) in the US in accordance with the advanced televisionsystem committee (ATSC) vestigial sideband (VSB) can be enhanced throughinformation exchange and mapping with respect to a dual transport stream(TS) which includes normal data and turbo data. As a result, the digitalbroadcasting transmission system provides not only the compatibilitywith existing normal data transmission systems, but also the improvedreceptivity under a variety of reception environments.

While not required, it is understood that aspects of the invention canbe implemented using software, hardware, and combinations thereof. Whiledescribed in terms of a broadcast signal sent through air or cable, itis understood that, the transmission can be made through recording on amedium for delayed playback in other aspects of the invention.

While the invention has been shown and described with reference tocertain embodiments thereof, it will be understood by those skilled inthe art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the invention as definedby the appended claims.

What is claimed is:
 1. A digital broadcast receiver, comprising: areception unit receiving a transport stream (TS) which comprises knowndata and additional data from a digital broadcast transmitter; a turbodecoder performing turbo-decoding of the additional data included in thetransport stream; and a processor performing Reed-Solomon (RS) decodingof the turbo-decoded additional data, wherein the TS further comprisesnormal data in addition to the known data and the additional data,wherein the known data is predetermined between the digital broadcastreceiver and the digital broadcast transmitter, and is different fromfield sync data and segment sync data, wherein the TS is transmittedfrom the digital broadcasting transmitter comprising a Trellis encoderto initialize internal memories used for Trellis-encoding at a beginningof the known data and to perform Trellis-encoding of the known data byusing the initialized internal memories and a parity generating unit toreceive data altered according to the Trellis-encoding and to generatean RS parity corresponding to the altered data so that an RS paritycorresponding to the data before being altered is replaced with theregenerated RS parity, and wherein the trellis encoder is initializedaccording to a control signal distinct from the transport stream.
 2. Thedigital broadcast receiver of claim 1, wherein the TS comprises theknown data and the additional data which are mixed in a single packet.3. The digital broadcast receiver of claim 1, wherein the TS comprisesthe additional data in a single packet.
 4. The digital broadcastreceiver of claim 1, wherein the TS comprises only the additional datain a data area of the TS.
 5. The digital broadcast receiver of claim 1,wherein in the TS, a predetermined number of packets comprising only theadditional data in a data area of the TS and a predetermined number ofpackets comprising the known data in a predetermined area of theadditional data are alternately repeated.
 6. The digital broadcastreceiver of claim 1, wherein in the TS, a predetermined number ofpackets comprising the known data in a predetermined area of theadditional data and a predetermined number of packets comprising thenormal data are alternately repeated.
 7. The digital broadcast receiverof claim 1, wherein in the TS, a predetermined number of packetscomprising the additional data and a predetermined number of packetscomprising the normal data are alternately repeated.
 8. The digitalbroadcast receiver of claim 1, wherein in the TS, a predetermined numberof packets comprising only the additional data in a data area of the TSand a predetermined number of packets comprising the normal data arealternately repeated.
 9. The digital broadcast receiver of claim 1,wherein in the TS, a predetermined number of packets comprising only theadditional data in a data area of the TS, a predetermined number ofpackets comprising the known data in a predetermined area of theadditional data, and a predetermined number of packets comprising thenormal data are alternately repeated.
 10. A reception method of adigital broadcast receiver, the method comprising: receiving a transportstream (TS) which comprises known data and additional data from adigital broadcast transmitter; performing turbo-decoding of theadditional data; and performing Reed-Solomon (RS) decoding of theturbo-decoded additional data, wherein the TS further comprises normaldata in addition to the known data and the additional data, wherein theknown data is predetermined between the digital broadcast receiver andthe digital broadcast transmitter, and is different from field sync dataand segment sync data, wherein the TS is transmitted from the digitalbroadcasting transmitter comprising a Trellis encoder to initializeinternal memories used for Trellis-encoding at a beginning of the knowndata and to perform Trellis-encoding of the known data by using theinitialized internal memories, and a parity generating unit to receivedata altered according to the Trellis-encoding and to generate an RSparity corresponding to the altered data so that an RS paritycorresponding to the data before being altered is replaced with theregenerated RS parity, and wherein the trellis encoder is initializedaccording to a control signal distinct from the transport stream. 11.The method of claim 10, wherein the TS comprises the known data and theadditional data which are mixed in a single packet.
 12. The method ofclaim 10, wherein the TS comprises the additional data in a singlepacket.
 13. The method of claim 10, wherein the TS comprises only theadditional data in a data area of the TS.
 14. The method of claim 10,wherein in the TS, a predetermined number of packets comprising only theadditional data in a data area of the TS and a predetermined number ofpackets comprising the known data in a predetermined area of theadditional data are alternately repeated.
 15. The method of claim 10,wherein in the TS, a predetermined number of packets comprising theknown data in a predetermined area of the additional data and apredetermined number of packets comprising the normal data arealternately repeated.
 16. The method of claim 10, wherein in the TS, apredetermined number of packets comprising the additional data and apredetermined number of packets comprising the normal data arealternately repeated.
 17. The method of claim 10, wherein in the TS, apredetermined number of packets comprising only the additional data in adata area of the TS and a predetermined number of packets comprising thenormal data are alternately repeated.
 18. The method of claim 10,wherein in the TS, a predetermined number of packets comprising only theadditional data in a data area of the TS, a predetermined number ofpackets comprising the known data in a predetermined area of theadditional data, and a predetermined number of packets comprising thenormal data are alternately repeated.
 19. The digital broadcast receiverof claim 1, wherein the trellis encoder is initialized by a valuelocated in the transport stream just before the known data is encoded bythe trellis encoder.
 20. The digital broadcast receiver of claim 1,further comprising an equalizer which compensates for channel distortionusing the known data.